Earth digging machine



Feb. 26, 1957 c. WALL EARTH nxccxuc MACHINE 4 Sheets-Sheet 1 Filed Oct. 15, 1951 Feb. 26, 1957 Filed Oct. 15, 1951 C. WALL EARTH DIGGING MACHINE 4 Sheets-Sheet 2 e/Go 21/522 Feb. 26, 1957 Filed Oct. 15, 1951 C. WALL EARTH DIGGING MACHINE 4 Sheets-Sheet 3 @vanWeo 2 62? 977' I afgomggg Feb. 26, 1957 c. WALL 2,782,534

EARTH DIGGING MACHINE Filed Oct. 15, 1951 I 4 Sheets-Sheet 4 I84 0 we I94 I 178 dfiorzggy United States Patent 2,782,534 EARTH DIGGING MACHINE Cleo Wall, Colfax, Iowa Application October 15, 1951, Serial No. 251,349

7 Claims. (Cl. 37-85) My invention relates to improvements in earth digging machines.

Earth digging machines may be found embodying various forms of construction and designed for many special purposes. Dozers, power shovels, earth augers, ditch diggers and the like have long been in use and in general are very efficient for their particular operations. They have, however, a more or less common characteristic in that their size, weight and bulkiness generally affects adversely their maneuverability and facility of transportation. Moving the larger earth digging machines usually requires an auxiliary vehicle such as a truck and trailer and those that are self-propelled must of course have ample room in which to move and operate.

In my invention I was motivated by a need for accomplishing a specific objective and in doing this, as will become apparent, I have developed a machine that is susceptible of many uses other than the specific task it was designed for. More specifically, my invention was designed to dig graves in cemeteries and in this regard many problems were presented. The terrain in most cemeteries is dotted with grave markers, headstones and shrubbery that are not always arranged in well defined rows and consequently any mechanical means for digging graves must not only be efficient for its intended purpose but must be capable of easily being maneuvered within the narrow confines of cemetery passageways.

Other problems created by the objects -I sought to accomplish related to the desirability of mechanically digging a hole that was not only of a predetermined size but which also was substantially free of all loose particles of dirt.

With these problems in mind one of the objects of my invention is to provide an earth digging machine capable of removing dirt from an area having such as would be usable for a grave, a septic tank in stallation, ditching or the like.

A further object of this invention is to provide an earth digging machine that is light in weight and is easily maneuverable through an obstacle filled area such as might be found in a cemetery.

Still another object of my invention is to provide a machine of the above class that is adjustable to produce an excavation perpendicular to the horizontal irrespective of the slope of the surface of the ground at the point of digging.

A still further object of this invention'is to provide on an earth digging machine of the type described, means for adjustably controlling the size of any particular excavation.

It is also an object of this invention to produce a ma chine as referred to above that will leave an excavation substantially free of any loose particles of dirt.

The use of buckets on an endless chain is embodied in my new machine and in this respect -I have as another object, the providing of automatic means on this maa calculated size chine for scooping the dirt from each bucket each time it has completed a digging operation.

Still another object of this invention is to provide in an earth digging machine, means for adjustably controlling the force of the digging element in relation to the hardness of the earth at the time of digging.

Further objects which I have accomplished and which will become apparent from the description to follow include making an earth digging machine that will leave a flat bottom and perpendicular sides in an excavation; that in the use of chain operated buckets has means for automatically releasing clods of dirt that may become wedged between the chain and its supporting structure, and a machine that is easily operable by one person.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

'Fig. l is a top plan view of my new earth digging machine,

' Fig. 2 is a perspective view of one corner portion of the supporting frame for this machine showing the means for adjusting the same relative to the horizontal,

Fig. 3 is an end view of my invention with the broken lines indicating different vertical positions for the digging and dirt conveying assembly,

Fig. 4 is a fragmentary elevational view showing the bucket scooping means on this machine,

Fig. 5 is a side elevational view, of my invention with the dotted and broken lines indicating different lateral and vertical positions for the corresponding structures,

Fig. 6 is an end view of the digging assembly taken from the line 6-6 of Fig. 5, and

Fig. 7 is a cross-sectional view of the bottom portion of the endless chain carrying the digging buckets toillustrate its construction for releasing wedged clods of dirt and the like.

Referring to the drawings, this machine is supported upon an elongated rectangular metal base frame 10,having the side members 11 and 12 and the end members 14- and 16. Preferably I have made this base frame from angle iron material to provide track means formed by the inwardly extending ledge or supporting shoulder portions 13, integral with the frame sides as shown in Fig. 1. On the outer side of the frame members 11 and 12 and extending in the same plane as the upper edge thereof is secured the guide rod 20 illustrated in Fig. .5. Mounted near each end of the frame members 11 and 12 on the outer side thereof is a caster wheel 22 which is adjustable (Fig. 5) to vary the position of the base frame relative to the horizontal. To accomplish this a short tubular member 24 is transversely secured to each spindle housing 2e at about its transverse median and a second tubular member 23 is similarly secured near the top of the housing 26 and on an opposite side from the tube 24 (Fig. 2). Thus, each wheel is in effect mounted, to a vertical housing 26 which has the two transverse bores provided by the tubes 24 and 28. Each tube 24 is rotatably mounted on a stub shaft 30 that extends from the frame sides, and detachably held therein by any suitable means such as the pins 32. Each tubular member 28 is rotatably arranged on one end of a pin 34 that is provided on its other end with an enlarged head portion 36 through which extends a threaded bore. An elongated threaded crank member 40 provided with a handle means 42 is rotatably and pivotally mounted on a suitable support 44 aifixed to the respective end portions of the frame members 14 and 16 so that each crank 40 is threaded into one of the pin heads 36. With this arrangement, rotation of the crank 40 will cause the tubes 24 to pivot on the pins 30 and thus move the wheels 22 asshown in Fig. 5. The use of caster wheels adds tothe maneuverability of the base frame and while casters are not required it is recommended that at least the two wheels on any one end of the base frame have this feature.

The entire superstructure of this device is secured to a separate metal frame means that is adapted to be mounted on the base frame 10 and laterally movable within the confines thereof. The base of this separate frame consists of the side members 46 and end portions 47 (Fig. 1) and has the reinforcing bar member 48 as shown in Fig. 6. It is rectangular in shape with axle means 50 secured at opposite ends thereon to carry the wheels 52.. The width of the frame base 46-47 with wheels 52 attached is such that the wheels will ride on two oppositely disposed tracks 18 of the base frame 10 as illustrated in Fig. 6, and the length of the frame base 46-47 is somewhat less than half of that of the inside of the base frame 10 (Fig. A keeper 53 is secured at opposite frame sides on the frame members 46 and adapted to engage the respective guide rods 20 as also shown in Fig. 5. A T-shaped support plate 54 (Fig. l) is secured between one of the frame ends 47 and the frame bar 48 and to one of the frame sides 46. Thus far described the separate frame means 46--47 is in effect divided into two rectangular frame portions by the frame bar 48. For purposes of better understanding the description to follow it is pointed out that the frame portion in which the T-shaped support 54 is located carries the motor, hydraulic means, gear box and other controls which will be later described and the other separate frame portion carries the higher frame superstructure on which is mounted the buckets and conveycrs. It will also be observed in Fig. 1 that relative to its base, the

, buckets 116 will travel up the diagonal side 115 of strucseparate frame portion having the T-plate 54 is slightly smaller than the portion carrying the higher superstructure and reference to the smaller or larger separate frame portions will be employed to clarify this description at times.

Referring now to the smaller separate frame portion, the outer corners thereof are defined respectively by vertical posts 56. A second set of posts 58 are oppositely disposed on the frame sides 46 and spaced slightly from the respective points where the frame bar 48 joins the separate frame sides 46. One each of the posts 56 and 58 are clearly shown in Fig. 5. Secured to the top of each pair of posts 56 and 58 extending outwardly from the posts 56 respectively are the bracket arms 60 and 62, on which is secured the platform 64. A source of power which I have shown as a gasoline motor 66 is suitably mounted on the platform 64 as illustrated in Fig 5. To the underside of the platform 64 I secure an oil reservoir means 68 for use with my hydraulic pressure as hereinafter described and a filler cap 69 for the reservoir 68 extends upwardly through the platform 64 for easy accessibility. On the T-plate 54 a bearing member 70 is mounted in which is journaled the shaft 72. One end of this shaft is associated with the bevel gears 74 and on the other end are the two pulleys 76 and 78. The pulley 76 is connected to a pulley 80 on the shaft 82 of the motor 66 by means of the belt 84 and a second belt 86 connects the pulley 78 to a hydraulic pump 88 which is also mounted on the T-plate 54 as shown in Fig. 1.

On the large separate frame portion the four corners thereof are defined by the relatively taller vertical posts 90, 92, 94 and 96 with the posts 92 and 96 being on the outer corners and the posts and 94 on the inner corners which coincide with the points at which the frame bar 48 joins the separate frame sides 46. The top of these taller'posts are secured together by the rail members'98 and apair ofparallel spaced apart support bars 100 and 102 are arranged diagonally across the top of the rails 98 and extend outwardly therefrom near post 90 and over the smaller frame portion as shown in Fig. 1. To facilitate the identification of these taller posts, the pertinent lead lines in Fig. l are directed to the boltlike end extensions extending through the rails 98.

A carriage means consisting of a pair of elongated bar members 104 secured in parallel spaced relationship by the transverse support member 106 is adapted to be vertically slidable within the frame structure formed by the posts 99, 92, 94 and 96. For this purpose each end of each bar 104 is provided with the arcuate plate 108 for engaging and partially embracingthe respective posts and thus each of the posts serves as a guide means for the carriage in its vertical movement. Mounted on the carrings and movable therewith is the bucket and chain assembly having a path of travel defined by an elongated triangular rigid structure 110 which has its narrow side at the bottom that is on a horizontal plane as shown in Fig. 6. This structure 110 consists of two complementary triangular bar frames having the vertical side 111, the bottom side 113 and the diagonal side 115 secured in spaced apart "relationship and has a cog wheel 112 mounted at each of the three corner points to carry the endless chain 114 on which is secured a plurality of spaced apart buckets 116, each with an arcuate digging edge 118 as shown in Fig. 5. A stop bar 116a extends outwardly from the bottom of each bucket 116 and is adapted to bear against the chain 114 as the bucket passes under the structure 110 for the purpose of limiting the tilt of the bucket and thereby limiting the extent of the bite which each bucket can take. In operation, the

ture 110 and down the vertical side 111 thereof as shown in Figs. 3 and 6. To provide means for taking slack out Of the chain 114 at times, I have made the upper and lower portions of the structure 110 separately and joined them (Fig. 6) to the respective extension bars 117 by means of the bolts and nuts 119. Each of these bars 117 is provided with the slots 121 so that if necessary, the frame-like structure 110is extensible sufiiciently to remove slack in the chain 114. The upper portion of the structure 110 is secured between the carriage bars 104 by the brackets 120, and at the bottom it is held against lateral movement as follows. On the outer side of the structure 110 and to the adjacent separate frame side 47 is mounted the upstanding brace 123 (Fig. 3), and a like brace 125 is mounted on the separate frame bar 48 on the opposite side of the structure 110 (Fig. 6). Secured to these braces 123 and 125 is the horizontal rod 127 on which is rotatably mounted the spool roller 129. A pair of vertical rod braces 131 extend respectively from the bottom sides 113 of the triangular structure 110 on opposite sides thereof to the upper portion of the diagonal sides 115 and in parallel spaced relationship from the inside edge of the vertical side 111 of said structure 110. This provides a track means that moves on the spool roller 129 as shown in Figs. 3 and 5. Thus, this roller guides the structure 110 in its vertical movements and the engagement of the respective spool ends (Fig. 5) on the respective outer sides of the vertical side 111 of structure 110 and the rod braces 131 restricts the lateral movement of the bucket and chain assembly.

Referring now to Fig. 7 I have illustrated how clods of dirt or the like 133 may become wedged between the chain 114 and the bottom 113 of the structure 110. To provide a means for automatically releasing such dirt, I have provided the slot 135 at one bottom corner of the structure 110. An elongated pair of bar members 137 secured by the transverse bar brace 139 are mounted betweent the bottom sides 113 so that its open ends extend inwardly adjacent the inside of the sides 113. These bars have an opening on one end adapted to register with the slot 135 and have the .slot 141 on their other ends. The slots 141 engage and are laterally movable on the pin 143 which extends transversely of and through the sides 113. 'The cog wheel 112 at this point is mounted so that its axle pin 147 extends through the slots 135 and the openings in the bars 137. A yieldable member such as the coil spring 149 or the like engages one side of the bar brace 139 on one end and the pin 143 on-its other end. Thus arranged, the spring 147 normally tends to keep the axle pin 147 at the outer end of the slot 135. However, a binding action from a clod of dirt 133 will cause the wheel 112 attached to the bars 137 to yieldingly move inwardly and thus provide slack in the chain as shown in Fig. 7 sufficiently to permit the dirt to drop free.

The cog wheel 112 at the top of the structure 111! is secured to a shaft 122 that extends outwardly therefrom in two directions as illustrated in Fig. 5, and has the cog wheels 124 and 126 arranged on its respective ends. A bracket arm 128 is secured to and extends horizontally inwardly from the top of the structure 110 adjacent the cog Wheel 124 and has its free end portion supported by the rod brace 130 that is anchored to the transverse car riage support 106. A bracket-like support 132 (Fig. 5) is secured to the bracket arm 128 and carries a stub shaft to which is secured the cog wheel 134 and one gear of the bevel gear assembly 136. The endless chain 138 is mounted on the cog wheels 124 and 134. As a part of the bevel gear assembly 136 there is the vertical stub shaft housing 14% through which is mounted the vertical bar shaft 142 that is operatively connected at its bottom to a socket member 144 which is attached to the bevel gear 74 by means of the universal joint 145. This socket 144 rotates with the gears 74, and the joint 145 compensates for any slight variations in direction of drive of the shaft 142 due to vibrations of the carriage 104 and its related parts while the buckets are in opera tion. The socket 144 has an internal square socket portion (not shown) and the shaft 142 is vertically adjustable to move into or out of engagement therewith whereby the operation of the gear assembly 136 is controlled. To accomplish this control of the shaft 142 I have provided a clutch means in the form of two spaced apart discs 146 mounted on the shaft 142 near its upper end (Fig. 6). For this purpose an ordinary pulley wheel has been found to be satisfactory. A pair of arms 148 arranged between the discs 146 on opposite sides are secured to a rod 150 that is rotatably mounted to the top of the frame formed by the posts 99, 92, 94 and 96. A lever handle 152 is secured to one end of the rod 150 (Fig. 5) so that a downward movement of the handle will move the arms 148 upwardly causing the shaft 142 to become disengaged from the socket assembly 144 and an upward movement of the handle will reverse the shaft movement and engage it with the socket 144. The handle 152 frictionally engages a rib 153 provided on the post 92 as shown in Fig. 5 to hold the handle against accidental movement.

Thus far described the carriage 104 which carries the structure 110 with the endless chain 114 and buckets 116, and the gear assembly 136 will normally move downwardlywithin the frame formed by the posts 90, 92, 94 and 96 by gravity, with the shaft housing 140 adapted to be vertically movable on the shaft 14-2. However since in the digging Operation of the buckets 116 which will later be described more in detail it is not always desirable to have the carriage 104 descending with the full force of its weight. I have provided certain carriage control means which I will nowdescribe.

When. the carriage 104 is in its uppermost position it can be held there against any downward movement by the vertical lock rod 154 as shown in Figs. 3 and 5. This rod is pivotally secured at its bottom to the brace 123 and near its top has the horizontal shoulder portion 156 that will removably engage the underside of the transverse support 106 on the carriage'104. A hori: zontal pull rod 158 having a knob handle 16!), is slidably mounted through the post 92 (Fig. 3) and is connected to the upper end of the lock rod 154. A spring member 162 suitably mounted on the pull rod 158 intermediate the post 92 and lock rod 154 normally holds the lock rod 154 in a position where its shoulder portion 156 will move under the support 106 whenever the latter reaches a vertical point above that of the shoulder.

The speed of the downward movement of the carriage and its associated parts and the movement of the carriage upwardly from its lowered position is accomplished by hydraulic means. For this purpose a hydraulic piston 164 (Fig. 6) is vertically mounted on the smaller frame portion near one of the posts 58 that is adjacent post (Fig. 5) so that the piston plunger 166 travels in a vertical plane. This piston is operatively connected to the hydraulic pump 88 (Fig. l) and the oil reservoir 68 by the hoses 168 in a well known manner. A manually operated valve control means 171) is placed in the hose line and suitably mounted on the bracket arm 60 as illus trated in Figs. 1 and 5. Also in the hose line is a manually operable by-pass valve 172 (Fig. 5) that serves as a control means for adjusting the speed at which the plunger 166 returns from its extended position. The free end of the plunger 166 carries a pulley wheel 174, and a vertical spring means 176 is secured at its lower end to the plunger just below the pulley wheel 174 and at its top to the inverted L-shaped rod support 178 (Figs. 5 and 6) that is secured at its bottom to one of the carriage bars 104. It is observed that the top of this rod 178 is spaced above the uppermost point of travel of the plunger and when the plunger is retracted the tension of the spring 176 on the pulley wheel 1'74- serves to steady the plunger and to prevent slack in cables hereinafter referred to so they will not jump their respective pulleys.

To operatively connect the carriage 1134 to the hydraulic means above described I have mounted on the carriage the rigid rod ball 1S6) (Figs. 3 and 5) having one end secured to the carriage transverse bar 104 and its other end secured to one of the braces 120, with a pulley wheel 182 suitably arranged on and extending upwardly from the top thereof. A flexible cable 184 (Fig. 3) is secured at one end between the bars and 102 (Fig. 1) is then reeved under the pulley wheel 182 on the bail 180, thence up to the bars 1% and 1112 and over the pulley wheels 186 and 188 secured therebetween (Fig. 3), thence downwardly and under the pulley 191) (Figs. 3 and 6) which is secured to the smaller separate frame adjacent the piston housing 164, thence upwardly and over the pulley 174 on the plunger 166 and thence downwardly to the brace 68 to which it is anchored (Fig. 6). Thus arranged, the carriage 104 and plunger 166 travel in the same vertical directions at the same time and when the carriage is at its lowered position, operation of the valve means will cause the plunger to rise and thus move the carriage upwardly and, if desired, to a point where it can be held against accidental downward movement by the lock rod 154. As the carriage moves downwardly, the lock rod 154 being reieased, the plunger will of course be retracted and in this operation the by-pass control 172 (Fig. 5) is adapted to adjust fluid pressure in the hose lines so that the speed of retraction of the plunger 166 can be selectively adjusted or downward movement of the plunger under the weight of the carriage can be stopped, if desired.

To the structure thus far described is associated a con veyor means 192 (Figs. 1, 3 and 6) for carrying the dirt from-the buckets 116 to a point of deposit. For this purpose I have secured to each of the arcuate plates 108 that engage respectively the posts 94 and 96, the oppositely disposed vertical bar members 194. A horizontal shaft 196 is rotatably mounted to these bars 194 at the bottom thereof and carry respectively the cog wheels 193 and 2110 (Figs. 1 and 6) each of which rotates adjacent the inner side of one of the bar members 194. One end of the shaft 196 extends outwardly from its adjacent bar 194 and carries the cog wheel 201 (Fig. 3). Hingedly mounted on the shaft 196 between the cog wheels 198 and 200 is an elongated conveyor platform 202 and on its outer end is the shaft 204 that has the cog wheels 206 and 208 on its respective ends. A latch rod 210 pivotally secured at one end to one of the bars 194 is adapted at its other end for detachable connection to the conveyor platform 202 for holding it in a horizontal position when in operation. An endless chain 212 (Figs. 3 and 5) connects the cog wheels 126 and 201 which transmits drive from the top of structure 110 to the shaft 196 at the base of the bars 194. Endless chains 214 and 216 on opposite sides of the conveyor platform 202 respectively connect the cog wheels 198 and 206, and 200 and 208. Secured to the chains 214 and 216 so to extend transversely of the platform 202 are a plurality of spaced apart buckets 218. These buckets 218 are synchronized with the buckets 116 so that one of the buckets 218 passes closely adjacent the chain 114 (Fig. 6) to receive the load from each bucket 116. The purpose of this is to carry away substantially all dirt from each bucket 116 and thus prevent dirt from falling back into the excavation as usually occurs when a conveyor belt is used in place of the buckets 218. The shaft 204 on the free end of the conveyor platform 202 is mounted in the spring loaded bearing member 219 underneath the platform 202 (Figs. 3 and 6) which serves to eliminate slack in the conveyor chains 214 and 216.

Referring now to Fig. 4 I wish to describe one of the novel features of this machine; namely, a means for scooping the dirt free from each bucket 116 each time it has picked up a load of dirt or the like and is about to discharge it. It is well known that in any digging operation, variations in the moisture content of the soil affects the degree of adherence of the soil to the digging implement. digger as here shown may well travel its course without dumping its full load and this will obviously alfect the efficiency of the entire operation. Therefore in my scoop means I provide a rod 220 rotatably mounted between the bars 194 at the top thereof. Secured to this rod 220 is a stem member 222 which extends inwardly and downwardly therefrom and preferably has a rectangular fiat scoop blade 224 on its free end. On one end of the rod 220 there is the lug 226 which is engageable with the boss 228 extending from the inside of one of the bars 194. This limits the rotation of the rod 220 in one direction and defines the upper limits to which the scoop blade 224 can move. A spring means 230 is mounted on the rod 220 so that when forces moving the scoop blade 224 downwardly are released, it will automatically return to its uppermost position. This scoop is positioned relative to the path of the buckets 116 over the top of structure 110 so that as each bucket passes this point with a full load, its open end will envelop the scoop blade 224 as illustrated. As the bucket continues its downwardly travel towards its dumping position, the scoop stem 222 is moved downwardly causing a scooping or digging action within the bucket that helps free the dirt therein for deposit in one of the conveyor buckets 218. The scoop after operating as just described will automatically return to position for similar engagement with the next bucket 116. Thus, each bucket 116 is cleaned each time it passes this scoop means.

As previously pointed out the separate frame means 4647 and all the superstructure carried thereon is movable within the base frame on the roller wheels 52. Controls for this movement may be accomplished in various ways but preferably I show manually operated cable means as follows. A pulley 232 is secured to the base frame end member 14 and a pulley 234 is similarly secured to the opposite base frame end 16 as shown in Fig. 1. A crank means 236 is secured between the braces 60 and 62 (Fig. l) and has the crank handle 238 on one When this adherence is great a bucket end. Spaced apart on the crank 236 are two spools 240 I and 242.

A cable 244 wound on the spool 240 is reeved over the secured to the opposite side 47 of the frame 46-47.

Suitable other spools or pulleys such as 248 (Fig. 1) for cable 244 and 250 (Fig. 6) for cable 246 are mounted on the separate frame to align the cables for a horizontal pulling force as further shown in Fig. 5. The spools 240 and 242 on the crank 236 are wound so that as cable on one is played out the cable on the other is wound up. Thus by selectively turning the crank handle 238 the entire superstructure of this machine can be laterally moved within the confines of the base frame 10 in two directions. On the crank 236 adjacent the handle I provide a ratchet-like wheel 252 that is engageable by the lock arm 254 which is pivotally mounted on the brace 60. This arm 254 is manually movable whereby the crank 236 can be locked at any time against rotation in either direction. 7

This machine when constructed as described will operate in the following manner. It will be observed that the base frame 10 is rectangular in shape and movable on caster wheels. This provides considerable maneuverability in moving this machine through narrow passageways such as may be found in cemeteries. I will thus describe the use of my invention relative to digging a grave but it will be appreciated that it is adaptable for digging purposes other than that required in cemeteries.

Moving digging equipment to a designated spot in a cemetery for digging a grave is complicated by the location of grave stones, trees, shrubbery and the like, but the construction of my machine as described reduces this problem to a minimum. Once the machine is on the site, each corner of the base frame is adjustable relative to the horizontal even though the ground at the grave site may be uneven. This is accomplished by selectively rotating each of the cranks 40 to raise or lower the base frame at the respective corners and thus positions this machine for digging a grave having walls perpendicular to the horizontal. The separate frame 4647 carrying the entire superstructure is then moved to its extreme position at one end of the base frame 10 by the rotation of the crank 236 and the digging operation is ready to commence.

The motor 66 operates the gear means 74 that is engageable with the gears 136 for moving the buckets 116 about the triangular structure 110. These buckets are designed to move up the diagonal side 115, down the vertical side 111 and across the bottom side 113 so that as the buckets 116 dig from the soil 256 the bite leavesa horizontal surface as shown in Fig. 6. As the buckets commence their bite at the bottom of the vertical side 111 of structure it is observed that resistance of the soil would normally cause the buckets to tilt away from the chain 114 with the result that each bucket would take a substantial bite necessitating a motive source adequate to pull it through. However, by providing the stop bars 116a on each bucket 116, the size of the bites is effectively controlled and consequently requiring a source of power considerably less than would be the case were the buckets not so controlled. Once the buckets 116 have been put in motion the lock rod 154 is released by pulling the knob handle and this frees the carriage 104 to move downwardly by gravity under its own weight as the depth of the excavation becomes greater. However, since the full weight of the carriage and its related members may be too great at times for efficient digging 1 have connected the carriage to the vertically movable hydraulically operated plunger 166. Thus by means of the bypass valve 172 the pressure in the hose lines can be regulated to resist the unrestricted retraction of the plunger 166 and thus allows the carriage to be eased down as desired. When cutting frozen ground, this allows the carriage to be adjusted in its descent so that relatively small bites are made by the buckets.

With regardto the conveyor means described it is obesrved that buckets are used instead of a belt conveyor. The reason for this is to assure that all dirt and the like from the digging buckets are caught and carried away so that loose dirt does not fall back into the grave. If the digging buckets merely dumped their load on a belt it is obvious that a good deal of it would be jarred ofli into the grave or fall directly into it. Graves should be free of loose dirt and consequently I have carefully synchronized the conveyor buckets so that one will be in position to catch dirt from each digging bucket as it empties its load.

The scoop means shown in Fig. 4 will operate automatically when this machine is in digging operation and this element can of course be adapted to any digging mechanisms having buckets running on an endless chain or the like.

In constructing this machine for use substantially for digging graves it is pointed out that the posts 92, 94, 96 and 98 can be of such a height so that the lowermost position of the carriage means will place the bottom of the structure 110 at the usual depth for graves. Also, the horizontal distance of the bottom side 1113 can be made to correspond with the width of an ordinary grave. These dimensions are not critical but merely convenient.

After the carriage has completed one full downward movement, the operation of the valve 170 will cause the plunger 166 to move upwardly and thus return the carriage to its upward position. The separate frame means is then moved laterally by means of the crank 236 a distance equal to substantially that of the buckets 116. Another complete descent of the carriage is effected which obviously makes the hole larger by the width of the bite of the buckets. These operations are repeated until the hole is of the desired length as indicated by the broken lines 258 in Fig. 1.

When this point thas been reached, the carriage is left at its lowermost position and with the buckets in operation the separate frame is slowly moved to the opposite end of the base frame. This operation will remove from the bottom of the grave any loose dirt that might be there and also level off the bottom which might have small ridges due to the arcuate shape of the cutting edges of the buckets 116.

In the use of this machine I wish to point out that the depth of the excavation can be selectively varied within the vertical limits of the carriage and of course the length thereof is determined by the number of times the digging buckets are permitted to make a descent. Consequently it is observed that excavations for purposes other than graves can be made by this machine.

Some changes may be made in the construction and arrangement of my earth digging machine without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In an earth digging machine, a base frame member having a plurality of wheels for moving the same over the ground, a plurality of separately operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a pulley on each of two opposite ends of said base frame, a separate frame member having roller Wheels thereon and movable on said base frame respectively towards and away from each of said pulleys, a crank means on said separate frame, a pair of cable members separately wound on said crank means and secured at one end to said separate frame member, the intermediate portion of each cable member reeved respectively over one of said pulleys whereby the selective rotation of said crank will move said separate frame member on said base frame in two directions respectively, a gear means on said separate frame member, a socket member connected to said gear means by .a universal joint, a source of power on said separate frame 'means operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, a hydraulic pump on said separate frame member operatively associated with said source of power, a fluid reservoir on said separate frame member, a hydraulic cylinder having a plunger moving in a vertical plane mounted on said separate frame member, hose means connecting said hydraulic motor, fluid reservoir and hydraulic cylinder, cable and pulley means connecting the free end of said plunger to the top of said carriage means whereby said plunger and said carriage means move in the same vertical direction at the same time, manually operable valve means associated with said cylinder for controlling the speed of the movement of said plunger, a triangular frame structure having a horizontal bottom side mounted on said carriage means and vertically movable therewith, an endless chain extending in atriangular path around said triangular structure, a plurality of spaced apart buckets on said endless chain, a stop bar member.

extending from each of said buckets adapted to engage said endless chain and thereby limit the tilt of said buckets for the purpose of controlling the size of its bite, a gear means on said carriage means associated with said endless chain for rotating the same, a shaft member disconnectibly associated at one end with said socket member and connected at its other end to said second mentioned gear means, manually operable clutch means on said shaft for connecting and disconnecting it with said socket member, a conveyor member mounted on said carriage means having a pair of endless chains respectively oppositely disposed thereon, said last mentioned chains operatively connected to said second mentioned gear means, a plurality of spaced apart buckets on said last mentioned chains synchronized with said first mentioned buckets so that each time a bucket on the first mentioned endless chain dumps its load, a bucket from the conveyor will be in position to receive it, a scoop means for cleaning each of said first mentioned buckets each time they pass a predetermined point when said chain is in operation, comprising, a scoop member pivotally secured to said carriage means and extending into the path of said first mentioned buckets at a point where they will normally commence the discharge of their load, said scoop member being enveloped by each bucket each time they pass said last mentioned point, the movement of said buckets cansing said scoop member to move therewith until said buckets move free of said scoop member, said scoop member when moving within said bucket effecting a scoop action against material carried therein, and means on said scoop member for automatically returning it to original position for association with successive buckets on said chain.

2. In an earth digging machine, a base frame having wheel means for movement of the same over the ground, manually operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a separate frame member having rollers thereon and movable on said base frame, manually operable means for selectively moving said separate frame member in'two directions, a gear means on said separate frame member,.a source of power on said separate frame member operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged Within said vertical frame structure and vertically movable therein, means on said separate frame associated with said carriage for controlling its movement in two directions, a triangular frame structure having a horizonal bottom side mounted on said carriage means and vertically movable therewith, an endless chain provided with a plurality of spaced apart buckets arranged on said triangular structure and having a triangular path defined thereby, a yieldable means on the bottom of said triangular structure engageable with said endless chain whereby if a 1 1 clod" ofdirt or the like becomes wedged between said endless chain and the bottom of said triangular structure said endless chain is yieldably movable to produce slack therein so that said dirt can fall free, a gear means on said carriage means operatively connected to said endless chain, a shaft member connecting each of said two mentioned gear means, clutch means for engaging and disengaging said shaft with one of said gear means, conveyor means mounted on said carriage and synchronized with said buckets for receiving dirt and the like therefrom and carrying it to a point of deposit, and said conveyor means operatively connected to said second mentioned gear means.

3. In an earth digging machine, a base frame having wheel means for movement of the same over the ground, manually operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a separate frame member having rollers thereon and movable on said base frame, manually Operable means for selectively moving said separate frame member in two directions, a gear means on said separate frame member, a socket member connected to said gear means by a universal joint, a source of power on said separate frame member operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, means on said separate frame associated with said carriage for controlling its movement in two directions, a triangular frame structure having a horizontal bottom side mounted on said carriage means and vertically movable therewith, an endless chain provided with a plurality of spaced apart buckets arranged on said triangular structure and having a triangular path defined thereby, a yieldable means on the bottom of said triangular structure engageable with said endless chain whereby if a clod of dirt or the like becomes wedged between said endless chain and the bottom of said triangular structure said endless chain is yieldably movable to produce slack therein so that said dirt can fall free, a gear means on said carriage means operatively connected to said endless chain, a shaft member disconnectibly associated at one end with said socket member and connected at its other end to said second mentioned gear means, clutch means for engaging and disengaging said shaft with said socket member, conveyor means mounted on said carriage and synchronized with said buckets for receiving dirt and the like therefrom and carrying it to a point of deposit, and said conveyor means operatively connected to said second mentioned gear means.

4. In an earth digging machine, a base frame having wheel means for movement of the same over the ground, manually operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a separate frame member having rollers thereon and movable on said base frame, manually operable means for selectively moving said separate frame member in two directions, a gear means on said separate frame member, a source of power on said separate'frame member operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, a hydraulic pump on said separate frame member operatively associated with said source of power, a fluid reservoir on said separate frame member, a hydraulic cylinder having a plunger moving in a vertical plane mounted on said separate frame member, hose means connecting said hydraulic pump, fluid reservoir and hydraulic cylinder, cable and pulley means connecting the free end of said plunger to the top of said carriage means whereby said plunger and said carriage means move in the same vertical direction at the same time, manually operable valve means. associated with said cylinder for controlling the speed of the movement of said plunger, a triangular frame structure having a l v 12 a horizontal bottom side mounted on said carriage means and vertically movable therewith, an endless chain provided with a plurality of spaced apart buckets arranged on said triangular structure and having av triangular path defined thereby, ayieldable means on the bottom of said triangular structure engageable with said endless chain whereby if a clod ofdirt or the like becomes wedged betweenlsaid, endless. chain and the bottom of said triangular structure said endless chain is yieldably movable to produce slack therein so that said dirt can fall free, a gear means on said carriage means operatively connected to said endless chain, a shaft member connecting each of said two mentioned gear means, clutch means for engaging and disengaging said shaft with one of said gear means, conveyor means mounted on said carriage and synchronized with said buckets for receiving dirt and the like therefrom and carrying it to a point of deposit, and said conveyor means operatively connected to said second mentioned gear means.

5. In an earth digging machine, a base frame having wheel means for movement of the same over the ground, manually operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a separate frame member having, rollers thereon and movable-on said base frame, manually operable means for selectively moving said separate frame member in two directions, a gear means on said separate frame member, a socket member connected to said gear means by a universal joint, a source of power on said separate frame member operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, a hydraulic pump on said separate frame member operatively associated with said source of power, a fluid reservoir on said separate frame member, a hydraulic cylinder having a plunger moving in a vertical plane mounted on said separate frame member, hose means connecting said hydraulic pump, fluid reservoir and hydraulic cylinder, cable and pulley means connecting the free end of said plunger to the top of said carriage means whereby said plunger and said carriage means move in the same vertical direction at the same time, manually operable valve means associated with said cylinder for controlling the speed of the movement of said plunger, a triangular frame structure having a horizontal bottom side mounted on said carriage means and vertically movable therewith, an endless chain provided with a plurality of spacedapart buckets arranged on said triangular structure and having a triangular path defined thereby, a yieldable means on the bottom of said triangular structure engageable with said endless chain whereby if a clod of dirt or the like becomes wedged between said endless chain and the bottom of said triangular structure said endless chain is yieldably movable to produce slack therein so that said dirt can fall free, a gear means on said carriage means operatively connected to said endless chain, a shaft member disconnectibly associated at one end with said socket member and connected at its other end to said second mentioned gear means, clutch means for engaging and disengaging said shaft with said socket member, conveyor means mounted on said carriage and synchronized with said buckets for receiving dirt and the like therefrom and carrying it to a point of deposit, and said conveyor means operatively connected to said second mentioned gear means.

6. In an earth digging machine, a base frame, a separate frame member having rollers thereon and movable on said base frame, manually operable means for selectively moving said separate frame member in two directions, a gear means on said separate frame member, a source of power on said separate frame member operatively connected to said gear means, a vertical frame structure, mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, means on said sepa rate frame associated with said carriage for controlling its movement in two directions, a triangular frame structure having a horizontal bottom side mounted on said carriage means and vertically movable therewith, an endless chain provided with a plurality of spaced apart buckets arranged on said triangular structure and having a triangular path defined thereby, a yieldable means on the bottom of said triangular structure engageable with said endless chain whereby if a clod of dirt or the like becomes wedged between said endless chain and the bottom of said triangular structure said endless chain is yieldably movable to produce slack therein so that said dirt can fall free, a gear means on said carriage means operatively connected to said endless chain, a shaft member connecting each of said two mentioned gear means, and clutch means for engaging and disengaging said shaft with one of said gear means.

7. In an earth digging machine, a base frame having wheel means for movement of the same over the ground, manually operable means on said base frame for adjusting it relative to the horizontal when on uneven ground, a separate frame member having rollers thereon and movable on said base frame, manually operable means for selectively moving said separate frame member in two directions, a gear means on said separate frame member, a source of power on said separate frame member operatively connected to said gear means, a vertical frame structure mounted on said separate frame member, a carriage means arranged within said vertical frame structure and vertically movable therein, means on said separate frame associated with said carriage for controlling its movement in two directions, an endless chain having a plurality of spaced apart buckets secured thereon and mounted on said carriage, the path of said chain being triangular in shape with a horizontal portion at the bot tom, gear means on said carriage and associated with said chain, a shaft member connecting each of said two mentioned gear means, clutch means for engaging and disengaging said shaft with one of said gear means, a bucket conveyor means mounted on said carriage and op eratively connected to said second mentioned gear means, and the buckets on said last mentioned chains synchronized with said first mentioned buckets so that each time a bucket on the first mentioned endless chain dumps its load, a bucket from the conveyor will be in position to receive it.

References (Jilted in the file of this patent UNITED STATES PATENTS 907,361 Hogan Dec. 22, 1908 994,380 Farrelly June 6, 1911 1,246,527 Bentson Nov. 13, 1917 1,341,138 Kincade May 25, 1920 1,365,748 Thorn Jan. 18, 1921 1,729,744 Knaver Oct. 1, 1929 1,866,037 Heim et al. July 5, 1932 2,041,616 Noell et al. May 19, 1936 2,169,184 French Aug. 8, 1939 2,472,758 Przybylski June 7, 1949 2,501,083 Owen Mar. 21, 1950 2,541,853 Armington et al. Feb. 13, 1951 2,545,377 Parisi Mar. 13, 1951 

